Thermo-structural analysis of space structures using Fourier tube elements

Space structures consisting of thin walled beams are subjected to incident solar heat flux and emit thermal energy by radiation. An improved thermo-structural analysis has been developed taking into account the nonlinear and time-dependent heat conduction and structural response in a circular tube space structure. The tube is modeled using the finite element method in the longitudinal direction, and the temperature gradient in the circumferential direction is predicted based on the Fourier series. The thermal and deflection analyses of a thin-walled tube beam suggests that the Fourier elemental model developed in this study can simulate accurately the thermo-structural behavior of tube structure, which agrees well with the predictions based on a conventional FE analysis and an analytical solution. The thermo-structural analysis of a more complex space parabolic antenna indicates that the Fourier elemental analysis can predict the change in focal length due to solar heat flux more accurately than the conventional FE analysis because of the consideration of the temperature difference in the cross-section of the beam in the Fourier elemental analysis.